#1 All students must perform all of the work of the activity in their science journals.

#2 When you are sure of your answer, transfer the information onto a mini whiteboard.

#3 The whiteboard work is to remain on the white board until it is approved.

#4 After your work is approved you are to become a student teacher and assist someone in the room who is having difficulty.

The evil Hugo A-Go-Go has stolen all of the water on the planet and is threatening to push Batfink, who is trapped in a barrel, off of the 52 meter high Canadian

Horseshoe Falls into the dried up Maid of the Mist Pool.

Batfink is 50 kg. He and the 25 kg. barrel are pushed with a 100N force over a distance of 10 m before leaving

the cliff. The force of friction is 8N.

How much time will Batfink have to escape from the barrel once it leaves the cliff? Karate is padding the

place where the barrel will land in case Batfink cannot free himself. How far away from the cliff should Karate

place the barrel catching device made of super foam?

What is the Fg on Batfinkand the barrel?

Show all of your work.

KNOWN WANT

m of Batfink = 50 kg. Fg

m of barrel = 25 kg.

Total mass = 75 kg.

GENERAL FORMULA

Fg = W = mg

75 kg. x 9.8N/kg = 735N

What is the Fs acting on Batfink and the Barrel if they are moving at constant velocity?

Show all of your work.

KNOWN WANT

mass = 75 kg. Fs

Fg = 735N

g = 9.8 m/s2

GENERAL FORMULA

ΣFy = may

Fs= W and since no acceleration, Fs = Fg = mg

Fs = (75 kg.)(9.8 m/s2)

Fs = 735N

Draw a force diagram of Batfink and the barrel while rolling on top of the cliff.

y

Fs 735N

Ff8NF 100N x

Fg735N

Calculate the acceleration of the barrel in the horizontal direction.

KNOWN WANT

mass = 75 kg. a

F = 100N

Ff = 8N

GENERAL FORMULA

ΣFx= max

Fa- Ff = max

100N - 8N = (75 kg)(a)

92N/75 kg = 1.23 m/s2

What is the Vf of the barrel just before it falls off the cliff?

KNOWN WANT

a = 1.23 m/s2 Vf

d = 10 m

Vo = 0 m/s

GENERAL FORMULA

Xf = Xo + Vo t + ½ at2 then V = at

10 m = (0 m/s)(t) + ½ (1.23 m/s2 )(t2)

10 m/.615 m/s2 = (t2)

16.26 s = t2

t = 4.03 s Vf = 4.96 m/s

How much time will Batfink have to escape from the barrel once it leaves the cliff?

KNOWN WANT

g = 9.8. m/s2 td = 52 mVo = 0 m/sGENERAL FORMULA

Yf = Yo + Vo t + ½ gt2

52 m = (0 m/s)(t) + ½ (9.8 m/s2 )(t2) 52 m/4.9 m/s2 = t2

10.61 s= t2

3.26 s = t

How far away from the cliff should Karate place the barrel catching device made of super foam?

KNOWN WANT

a = 1.23 m/s2 Xf

d = 52 m

Vo = 0 m/s

t = 3.26 s

GENERAL FORMULA

Xf = Xo + Vo t + ½ at2

Xf = 0 m + (4.95 m/s)(3.26 s)

Xf= 16.14 m